Vidalista contains Tadalafil, which is a PDE5 inhibitor used to treat erectile dysfunction (ED). It works by relaxing the blood vessels in the *****, allowing more blood flow to help achieve and maintain an erection. However, Vidalista (like other PDE5 inhibitors) can interact with nitrate drugs.  Who Should Avoid Taking Vidalista with Nitrate Drugs? People who are using nitrate drugs should avoid taking Vidalista due to the risk of a dangerous drop in blood pressure. Nitrate medications are often used to treat conditions like angina (chest pain), heart disease, and high blood pressure. When Tadalafil (the active ingredient in Vidalista) is taken with nitrate medications, it can cause a severe and potentially life-threatening drop in blood pressure, which can result in dizziness, fainting, and even heart attack or stroke.